Tree jack



Sept. 1", 1925;

L. HOUGHTON TREE JACK Filed M12. 4. 1924 9" M ATv-DRWEY Patented Sept. 1, 1925.

umreo STATES LELAND HOUGHTON, or SEATTLE, WASHINGTON.

. TREE JACK.

Application filed August 4; 1924. Serial No. 729,931.

T 0 all to 7mm it may concern:

Be it known that I, LELAND HOUGHTQN, a citizen of the United States,- residing at Seattle, in the county of King and State of Washington have invented acertain new and useful Improvement in Tree J acks. of which the following is a specification. 7 My invention relates to improvements in tree acks and the object of my invention is to provide a tree jack that is adapted for use in skyline logging operations and which is of light weight and substantial construction and eflicient in operation.

Another object is to provide a tree jack in which the cable is supported on an end "less grooved link belt that operates upon rollers that are disposed within the tree jack.

Another object is to provide a tree jack in which the cable is supported on an endless grooved link belt that operates upon rollers that are disposed in curved formation within the tree jack, the links of which belt being curved to comply with the curvat-ure formed by said rollers so as to alford an eflicient support having antifrietion features adapted to suport the cable when said cable is supporting heavy loads.

Other and more specific objects will be apparent from the following description taken in connection with the drawings.

Tree jacks of this nature are used extensively in skyline logging'operations and are usually of the form of pulleys mounted in blocks which construction causes it to be very heavy due to the fact that the frame must be made large and massive to-withstand the heavy loads and to the fact that a relatively large heavy pulley must be used to support the load and so that the cable will not be damaged by bending it too sharply in passing over the same. These tree jacks are used at high elevations on large spar trees and are very heavy and cumbersome to move around and diiiicult to secure in the proper elevated positions to the spar trees.

My invention makes possible a great reduction in the weight of tree jacks of this nature and yet provides a track surface of relatively large diameter over which the cable and link belt may pass.

I accomplish these objects by devices illustrated in the accompanying drawings, wherein Figure 1 is a somewhat diagrammatic vview in elevation illustrating the use of my tree jack on a spar tree;

Fig. 2 is a view in side elevation with parts broken away showing a preferred conupon which rollers 10 are rot-atably mounted,

the bolts 9 being arranged in the form of a curve or are with its convex side normally uppermost. Y 1

A link belt formed of sections 1 1 articulated by pivots 12 and grooved as at 13 for the receptionof a cable 14 is adapted to roll upon the rollers 10. The link belt formed, of the sections 11 is long enough so that it hangs in-a loop below the body of the tree jack.

In operation the cable 1 1 is passed through the tree jack between the side plates 5 and 6 so that it will rest upon the link belt and the jack is secured by any suitable meansvto the top of a spar tree 15 as shown in Fig. 1., When it isused in this man ner the cable 14E will fit within the groove 13 in the link belt and the cable and belt will ride upon the rollers as on an ordinary pulley.

My treejack is very much lighter in weight than the ordinary block and pulley due to the fact that the frame may beconstructed lighter and that the, pulley is entirely elimi nated and my tree jack has been found to be very efficient in operation when the direction of the cable in passing over the throughout jack is changed by an angle of less than ninety degrees.

In Fig. 3 I have shown a tree jack that differs slightly in construction from the tree jack shown in Fig. 2. This tree jack embodies two side plates 16 and 17 rigidly supported in relatively spaced parallel relation by a combined spacer and track member 18 and having a continuous trackway 20 Within which a plurality of rollers 21 are freely disposed: Alink belt 22 siibstantially identical with the link belt previusly described in connection With Fig. 2 'is' arranged torun on the pllears 21 for receiving a cable aspreviously described.

In operation the tree jack is secured to a support, as to the top of the spartree 15 and a cable 11 is'p as'sed thereover in such; a. manner as to make an angle or bend not in excess '61 iiiiie'ty degrees. the cable moves the link belt motes therewith and rolls upon the rollers 10 ,'o-r 21' thus taming a very arena for the cable one that does not were the cable. The!rollers 21 in tliestru'cture shown 111F133; 3 travel around in the tramway 20 and offer very little frictionalresistance to the 'mov nie tef the link belt.

20 The fs re oing description mid Erecti panying drawings clearly disclose a preferred embodiment of invention but it Will be understood that this disclosure is merely illustrative and that numerous changes may be made, in the structure Within the scope and spirit of the invention.

What I claim is: I p

A tree jack embodying a frame, a plurality of rollers closely mounted in curved formation in said frame, and an endless link belt carried by said closely mounte'dinllrs having a; groove for the reception of a cable, the links of said belt being curved to ply with the curvature formed by said closely mounted rollers and said belt being adapted to hang in a loop below said frame. h p

In Witness whereof, I l16f6l1l1l30 subscribe my name this'29tli' day of J my A. l). 1924;.

LELAND noueiirou. 

